[teentesla]

Hello,

For my honors chem class we have to do a upcoming lab using pipettes and filling them with gas to launch them, you win by getting the farthest distance. So I have a few questions to ask. Which gas would be better? H2 or methane? a BIGGER pipette or a smaller one? angle of launch? air to fuel ratio? Also how to light the gas, spark or match?

[billnotgatez]

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[teentesla]

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Ok, I think methane is better because there is more atoms for it to work. I think a smaller pipette would be better because I guessed and have no idea. I think a 45 degree angle is best and a 90% air to fuel ratio using a match.

Now Can I please get some help, thanks

[Arkcon]

Well, thanks for paying lip service to the forum rules, you're slightly ahead of many other people.  But you'll learn nothing with attitude, a random fact based on no chemical concepts at all, a guess, then two more unsupported concepts.  And learning is what we want this forum to be about, not who gets their pipettes farthest.

OK, you have to find another concept around how hydrogen and methane are different from each other.  You'll have to compare engineering concepts -- a bigger pipette hods more gas, a smaller one is lighter -- which factor wins?  You'll need to figure which angle is best, based on the physics of air resistance and gravity.

And this is a silly question, no honors high school is building hydrogen fueled pipette rockets.

[teentesla]

Well, thanks for paying lip service to the forum rules, you're slightly ahead of many other people.  But you'll learn nothing with attitude, a random fact based on no chemical concepts at all, a guess, then two more unsupported concepts.  And learning is what we want this forum to be about, not who get pipettes farthest.

OK, you have to find another concept around how hydrogen and methane are different from each other.  You'll have to compare engineering concepts -- a bigger pipette hods more gas, a smaller one is lighter -- which factor wins?  You'll need to figure which angle is best, based on the physics of air resistance and gravity.

And this is a silly question, no honors high school is building hydrogen fueled pipette rockets.

I don't know how to do any of those things, that's why I need y'all's help...
And my honors class is making hydrogen fueled pippete rockets, in fact we are gonna make some in about an hour. Can you please help me so I can "learn".

[curiouscat]

And my honors class is making hydrogen fueled pippete rockets, in fact we are gonna make some in about an hour.

Can you post photos / videos?

[curiouscat]

How exactly do you launch a pipette anyways? Fill with gas & set it on fire? Sounds pretty dangerous.

[Arkcon]

While you're sharing all that, do let us know the curriculum:  What concepts are being taught, what classes have been held to prepare you for this experiment, what pre-study questions have been assigned, what are you to report after you're done.  I'd expect a chemistry course to be covering that, as well.

[teentesla]

How exactly do you launch a pipette anyways? Fill with gas & set it on fire? Sounds pretty dangerous.

No, and don't be an idiot afraid of chemicals...

You fill it with water (by squeezing it and using the low pressure to get water into it) and then using a chemical reaction (such as HCl and Zinc to get H2) and a adapter to force the gas into the pippete, which would then push the water out. This gives you a rough estimate of the gasses in there and their ratios. Today we started experimenting and I found that that Hydrogen gas (60%) and oxygen gas (40%) yielded the best results. Although I did not have enough time to test out enough configurations to be sure...

Also you use a spark to get the combustion reaction to occur.

[teentesla]

While you're sharing all that, do let us know the curriculum:  What concepts are being taught, what classes have been held to prepare you for this experiment, what pre-study questions have been assigned, what are you to report after you're done.  I'd expect a chemistry course to be covering that, as well.

This is a new unit, so we don't know too much...

[408]

How exactly do you launch a pipette anyways? Fill with gas & set it on fire? Sounds pretty dangerous.

Your perceptions of danger are not based in reality. 

[Arkcon]

How exactly do you launch a pipette anyways? Fill with gas & set it on fire? Sounds pretty dangerous.

Your perceptions of danger are not based in reality.

I think curiouscat:'s concerns are reasonable, depending on other controls, and sizes.  I don't think much of the O.P's technique, it seems too random for a class meant to teach science, instead of just doing something cool.  Do you 408: have anything specific and demonstrative to support your point of view?

[curiouscat]

How exactly do you launch a pipette anyways? Fill with gas & set it on fire? Sounds pretty dangerous.

Your perceptions of danger are not based in reality.

He said "launch a pipette". Most pipettes I've seen are glass. Setting something made of glass into rapid motion sounded dangerous. Especially inside a lab.

He mentioned Methane. He mentioned H2. Both flammable gases. Handling both needs care. Especially if you speak of "launching" glass objects with it.

In hindsight, he's not using a glass pipette since he talks of squeezing it. Also, he seems to be "launching" water. Not the pipette itself.


So, pardon me, if my perceptions were based on an inaccurate description of the experiment.

[408]

  Do you 408: have anything specific and demonstrative to support your point of view?

Any number of child's experiment books or teachers' guides where this experiment is commonplace.

https://www.flinnsci.com/media/621403/91612.pdf

https://www.youtube.com/watch?v=QjWbMwFScac

[Arkcon]

I'll pass on the Youtube video, but that's a good, clear protocol with good explanations of what this experiment is supposed to teach.